Hypertension affects a disproportionate number of African-Americans as compared to European Americans. It has been suggested that this is due to a genetic predisposition that causes accentuated phenotypic differences in the US. In addition, it is well known that treatment of hypertension in Blacks is different from that in Whites. It is therefore important to understand the underlying genetics of this disease in African-Americans in order to better diagnose and treat affected individuals. Since the etiology of essential hypertension is complex, it is necessary to simplify any study of this disease to maximize the possibly of finding predisposing genes. I will do this by studying the disease in individuals from West Africa. Two things make this strategy more likely to succeed. First, West Africans are genetically more homogeneous than African-Africans; the African-American genome is approximately 30% European. Therefore, in the US many genetic analyses will be unable to detect genes with even a moderate effect because different predisposing genes may be present in the African-Americans as a whole and perhaps even the same family. This will make the detection of any of these genes difficult to impossible. Second, the disease is rarer in Africa,, making those individuals who are hypertensive more likely to have a genetic predisposition. The proposed study will recruit individuals from Ghana to study the association of several genes with essential hypertension. Two approaches will be taken in each of two study areas. First, random population samples will be collected from both hypertensive and normotensive individuals in Accra and rural villages. This association will be used to compare allele frequencies and genotype frequencies from individuals in the markers throughout the genome. The rural populations will be especially important as the incidence of hypertension in rural Africa is generally below 10% and individuals who have the disease in this environment are most likely to short the strongest genetic predisposition.